Brake



March 28, 1939. L. E. LA BRIE BRAKE Original Filed Nov. 22, 1950 2Sheets-Sheet INVENTOR LUDGEE E. LABElE ATTORNEY.

| E, LA BRIE BRAKE 1930 2 Sheets-Sheet Original Filed Nov. 22

w m E w fi m m W F m m e D M Patent Mar. 28, 1939 STATES PATENT -OFFICELudger E. La Brie,

Bendix Brake Company, corporation of Illinois Detroit, Mich., assignorto South Bend, Ind... a

Original application November 22, 1930, Serial Divided and thisapplication May 4, 1936, Serial No. 77,733

8 Claims.

feature of the invention relates to means for the development of airpressure for applying pressure to liquid in such a reservoir.

Various desirable and illustrative arrange ments are shown for keepingthe liquid in the reservoir under pressure and various features ofnovelty relate to these particular arrangements. Some of them utilizecompressed air as a pressure medium and others utilize vacuum, forexample the suction of the intake manifold of an engine, to supply airpressure on the liquid.

The above and other objects and features of the invention includingvarious novel and desirable details of construction will'be apparentfrom the following description of the illustrative embodiments, shown inthe. accompanying drawings, in which:

Figure 1 is a top plan view of an automobile chassis showing thearrangements of the parts of a system of hydraulic brakes;

Figure 2 is a side elevation of the chassis shown in Figure 1;

Figure 3 is a section through the liquid reservoir of the hydraulicsystem of Figure 1;

Figured is a corresponding section through a difierent form of liquidreservoir; and

Figures 5 and 6 are sections at right angles to each other through theparticular form of liquid reservoir which is illustrated in Figures 1and 2 and which in some respects is equivalent to those shown in Figures3 and 4.

The chassis shown in Figures 1 and 2 includes the usual chassis frame 38supported by the usual springs on front and rear axles (not shown)carried by front wheels 32 having brakes indicated generally at 3d andon rear wheels 36 having brakes also indicated generally at 36.

The brakes are intended to be operated by a hydraulic system includingflexible hose connec tlons 38 adjacent the four wheels and communicatingby suitable pipe 10 carried by the chassis frame 36 with. the outlet d2of a master cylinder assembly M which may contain an operating pistonconnected with the usual brake pedal 48. The hydraulic system'is keptfull of liquid by means of a reservoir which may be of one of the formsshown in Figures 3, 4, 5 or 6 and which is mounted on the dash above themaster cylinder and on the oppositesidc of the dash from the driver. Thereservoir 50 is connected to the master cylinder 44 by means such as aflexible conduit 52.

The form of reservoir shown in Figures 5 and 6 and which is shown forconvenience diagrammatically in Figures 1 and 2 includes astamped steelcontainer divided vertically into two parts by a flexible diaphragm 54,which may be made 5 of rubberized fabric or other flexible materialwhich will not be affected by the liquid used in the hydraulic system.The part 56 to the left of the diaphragm in Figure 5 contains thereserve supply of liquid, which may be introduced 10 through a fillercap 58 and is formed with an outlet 60 to which the conduit 52 isattached. The part 62 to the right of the diaphragm in Figure 5 isprovided with means such as an ordinary tire valve 64 compressed airfrom a tire pump or from the usual air line found in filling stationsand garages. It is intended that a pressure of some ten pounds becarried in the space 62, this being just suflicient to insure that theentire hydraulic sys- 20 tem is at all times under a pressure suflicientto prevent any sucking in of air and which is yet light enough so thatit does not actually apply the brakes.

As shown in Figure 3, instead of the com- 5 pressed air pressureutilized in Figures 5 and 6, I may provide a connection 66 from theintake manifold of the engine which maintains a partial vacuum in thespace 68 in the lower part of a reservoir housing upon which theatmospheric air may act through an opening it in the cover it.Preferably, the diaphragm 1? acts on the liquid by means such as a cap18 forming a sort of piston adapted to compress a flexible bag orauxiliary diaphragm 35 device 89) within which the liquid is containedand which communicates through an outlet 82 to the conduit 52. By thisarrangement the vacuum of the intake manifold maintains air pressurethrough the opening M on liquid serving 40 as before to keep a lightpressure of some ten pounds on thehydraulic system. In order to preventundue pressure being built up, I may provide an inwardly opening checkvalve 88 for the space such a tension that the valve will Open when thepressure in the space 68 drops below the critical predetermined limit. v

In the arrangement of Figure 4, the connection 66 from the intakemanifold opens into a flexi- 50 ble corrugated metallic diaphragm 86which is cup-shaped in form and which is secured at its lower mouth to astamping 88 secured to the cap 90 closing the lower end of an externalhousing 92. The upper end of the corrugated cup-shaped as so that it maybe filled with 15 it below a diaphragm i2 30 68 which is held by aspring having 5 diaphragm 86 is secured to a base stamping 94 whichurges downwardly a corresponding base 96 closing the upper end of asimilar corrugated metallic diaphragm 98 which contains a reserve supplyof liquid and the mouth of which is closed by a stamping I00 secured tothe cap 90. The liquid inside the cup-shaped diaphragm 98 communicateswith the conduit 52 through an outlet I02.

Both the containers and 98 may be filled by providing a suitable fillerspout I04 with a removable cap.

While a number of illustrative embodiments of the invention have beendescribed in detail, it is not my intention to limit its scope to theseparticular embodiments, or otherwise than by the terms of the appendedclaims.

This application is a division of my copending application Serial No.497,383, flled November 22, 1930, now Patent No. 2,095,752, datedOctober 12, 1937.

I claim:

1. A brake system comprising hydraulic brakeoperating connections, asource of fluid pressure, and a reservoir containing coaxial corrugatedmetal diaphragms one positioned within the other, the inner onecontaining liquid and com-- municating with said connection whenever thebrakes are released, and the outer one continuously in communicationwith said source and arranged to exert air pressure on the inner onewhen the brakes are released.

2. A brake syst-em comprising hydraulic brakeoperating connections, asource of fluid pressure, a reservoir containing coaxial corrugatedmetal diaphragms one positioned within the other, the inner onecomprising a fluid tight container for liquid entirely sealed from theouter container and communicating with said connections when the brakesare released, and the outer one continuously in communication with saidsource and arranged to exert air pressure on the inner one when thebrakes are released, and means actuated by said source for drawing airfrom the outer metal diaphragm for exerting air pressure on the innerdiaphragm.

3. A brake system reservoircomprising a metal container having a. ventto the atmosphere, a flexible corrugated metal diaphragm within saidcontainer, means for connecting a source of suction with the interior ofsaid diaphragm, and an inner flexible corrugated metal diaphragm withinthe first named diaphragm, entirely sealed therefrom, and adapted tocontain liquid to be used in the operation of the brakes.

4. A brake system reservoir comprising a metal container having a ventto the atmosphere, 9. flexible corrugated metal diaphragm within saidcontainer, means for connecting a source of suction with the interior ofsaid diaphragm, a pressure limiting check valve for said diaphragm, aninner flexible corrugated metal diaphragm within the first nameddiaphragm, entirely sealed therefrom and from said source of suction,and means for supplying liquid to said inner diaphragm to be used in theoperation of the brakes.

5. In a hydraulic brake system having a master cylinder, conduits andwheel cylinders, a reservoir for brake fluid comprising a metalcontainer, 8. flexible diaphragm dividing said container, means forfilling the container on one side of the diaphragm with fluid for thebrake system, means for conducting the fluid to the master cylinder ofthe brake system, and means for exerting air pressure on the other sideof the diaphragm, all so constructed and arranged to maintain a pressurein the wheel cylinders when the brakes are released.

6. In a hydralic brake system having a master cylinder, conduits andwheel cylinders, a reservoir for brake fluid comprising a metalcontainer, a flexible diaphragm dividing said container, means forfilling the container on one side of the diaphragm with fluid for thebrake system, means for conducting the fluid to the master cylinder ofthe brake system, and means for exerting air pressure on the other sideof the diaphragm said last-named means comprising a second diaphragmcoaxial with and surrounding the first, and means for connecting oneside of the second diaphragm to a source of suction, said metalcontainer being formed with a vent on the other side of the seconddiaphragm, all so constructed and arranged to maintain a pressure in thewheel cylinders when the brakes are released.

- '7. In a hydraulic brake system having a master cylinder, conduits andwheel cylinders, a reservoir for brake fluid comprising a metalcontainer, a flexible diaphragm dividing said container, means forfilling the container on one side of the diaphragm with fluid for thebrake system, means for conducting the fluid to the master cylinder ofthe brake system, and means for exerting air pressure on the other sideof the diaphragm, said last named means comprising a second diaphragmcoaxial with and surrounding the first, means for connecting one side ofthe second diaphragm to a source of suction, said metal container beingformed with a vent on the other side of the second diaphragm and. with avent on said one side of the second diaphragm having an inwardly openingspring closed valve, all so constructed and arranged to maintain apressure in the wheel cylinders when the brakes are released.

8. In a hydraulic brake system having a master cylinder, conduits andwheel cylinders, a reservoir for brake fluid comprising a metalcontainer, a flexible diaphragm dividing said container, means forfilling the container on one side of the diaphragm with fluid for thebrake system, means for conducting the fluid to the master cylinder ofthe brake system, and means for exerting air pressure on the other sideof the diaphragm, said last-named means comprising a threaded stemcontaining a check valve through which air may be pumped, all soconstructed and arranged to maintain a pressure in the wheel cylinderswhen the brakes are released.

LUDGER E. LA BRIE.

